Semi-purified rabbit antibody to the cholesterol esterase of rat pancreas has been prepared. This antibody will be used in preparing affinity chromatography columns for further scaling up of the isolation procedure for cholesterol esterase. The antibody will also be used in determining the cross-reactivity of the low energy cholesterol esterases in other tissues than pancreas, and also for the localization of cholesterol esterase in the intestinal mucosa. There will be continuation of our studies in isolated intestinal cells in respect to cholesterol and fatty acid uptake, the formation of lipoproteins in these cells, and their release into the media. Cholic acid analogues coupled to a non-absorbable resin carrier will be prepared and tested in the prevention of the absorption of cholesterol. In vitro and in vivo experiments with a series of fibers as binders of bile acids and/or cholesterol, and their effect on cholesterol absorption, will be carried out.